300 WALNUT FAMILY. 



104. PLATANACE^S, PLANE-TREE FAMILY. 



This order, if it may be so called, consists merely of the small 

 genus 



1. PL AT ANUS, PLANE-TREE. (The ancient name of the Oriental 

 species, from the Greek word for broad, alluding either to the leaves or the 

 wide-spreading branches.) Flowers monoecious, in separate naked heads 

 hanging on slender peduncles ; the sterile of many short stamens with club- 

 shaped little scales intermixed ; the fertile of club-shaped or inversely py- 

 ramidal ovaries mixed with little scales and tipped with a slender awl-shaped 

 simple style, ripening into a sort of akene with a tawny-hairy contracted 

 base. No evident calyx. Leaves alternate, palmately lobed or angled, the 

 hollowed base of the petiole covering and concealing the axillary bud (Les- 

 sons, p. 22, fig. 50) : stipules sheathing, like those of the Polygonum Family. 

 Fl. spring. 



P. OCCident&lis, AMERICAN PLANE, SYCAMORE, or BUTTONWOOD. 

 Well-known large tree by river-banks, with white close bark separating in thin 

 brittle plates ; leaves truncate or heart-shaped at base, rather scurfy-downy 

 until old, the short lobes sharp-pointed, and fertile heads solitary. 



P. orientlis, ORIENTAL PLANE, especially its var. ACERIFOLIA, seldom 

 planted in tlu's country, is very like ours, but has leaves more cut and sooner 

 smooth, the heads larger. 



105. JUGLANDACE^E, WALNUT FAMILY. 



Trees with alternate pinnate leaves, no stipules, and monoecious 

 flowers ; the sterile ones in catkins with an irregular calyx and 

 several stamens ; the fertile single or 2 or more in a cluster, with a 

 3-5-lobed calyx, the tube of which is adherent to the ovary. 

 The latter is incompletely 2 4-celled, but has only a single ovule, 

 erect from its base, and ripens into a large fruit, the bony inner part 

 of which forms the nut, the fleshy at length dry outer part the 

 husk. Seed 4-lobed, filled with the fleshy and oily embryo, the 

 large and separated cotyledons deeply two-lobed and crumpled or 

 corrugated. 



1. JUGLANS. Sterile flowers in solitary catkins from the wood of the preceding 



year, each with 12 - 40 stamens on very short filaments. Fertile flowers on 

 a terminal peduncle, with a 4-toothed calyx, 4 little green petals, and 2 clnb- 

 shaped and fringed conspicuous stigmas. Husk of the fruit drying up with- 

 out splitting. Bark and shoots resinous-aromatic and strong-scented. Buds 

 several, one over the other, the uppermost far above the axil (Lessons, p. 27, 

 fig. 52). Pith in plates. Leaflets numerous. 



2. GARY A. Sterile flowers in clustered lateral catkins, with 3-10 almost sessile 



anthers. Fertile flowers 2 -5 in a cluster on a terminal peduncle: no petals: 

 stigmas 2 or 4, large. Husk of the fruit splitting into 4 valves and falling 

 away from the smooth nut. Valuable timber and nut trees, with very hard 

 and tough wood, and scaly buds single (Lessons, p. 22, fig. 49), from which 

 are usually put forth both kinds of flowers, the sterile below and the fertile 

 above the leaves. 



1. JUGLANS, WALNUT. (Name from Jovis glans, the nut of Jupiter.) 

 Fl. spring : fruit ripe in autumn. Seed sweet and edible. 

 * Native trees of the country: nut with very rough and fnrroived surface, from 



which the dried husk does not fall away : seed very oily. 



J. cin&rea, BUTTERNUT or WHITE W. Middle-sized tree, mostly X. : 

 stalks and shoots clammy-downy; leaflets downy, at least beneath, oblong- 

 lanceolate, pointed, serrate ; fruit obloug J nut with very rugged ridges. 



